Effect of natural media amendments on crop quality under controlled environmental conditions

Abstract

The effect of different natural media amendments on the physical, chemical, and biological properties of soil is well studied and documented. Although there is more information on changes in soil parameters, few studies have demonstrated effects on crop quality. Herein, a greenhouse study was set up to identify the effect of wood ash (WA), paper sludge (SL), biochar (BC), and its combinations on kale’s nutritional profile grown in two different soil types (soil type 1, soil type 2) in Newfoundland, Canada. Pathway analysis revealed that although the same media amendments were used, the kale quality parameters were significantly altered by the grown soil type. It was shown that for soil type 2, most of the parameters were significantly enhanced compared to CTL (control) (p<0.05). For soil type 1, upon the addition of WA, SL, and BC there was a significant increase in the marketable yield; however, the crop’s nutritional parameters were not significantly changed. The lipidomics results showed that for soil type 1, WSBC (wood ash+sludge+biochar) amendment appeared to be effective in enhancing the functional lipids of 1,2 DGs, 1,3 DGs, ω6 lipids, and phospholipids. Whereas in kale grown in soil type 2, most of the studied functional lipids were increased upon the addition of SL and WBC (wood ash+biochar) media amendment. This different impact of media amendments on soils was also suggested from the pathway analysis revealing significantly different (p<0.05) lipid pathways associated with each soil type. In conclusion, WA, SL, and BC and the combination amendments showed a positive effect on kale’s nutritional profile, and this approach can be used to produce functional foods in controlled environmental conditions.